I don' 'no nuffin 'bout watermakers, Scott
I do know that the Sea-land Industries you mention is NOT the same SeaLand Technology that makes the VacuFlush, though. A lot of the folks who hang out on the Cruising World Bulletin Board are blue water sailors who have considerable experience with watermakers...ask them what they think of it. Have a link to any website handy when you post your question, so they can look at it. But I can answer your toilet question: No...you cannot convert a manual marine toilet to fresh water flush without risking polluting your potable water. If there were a way to do it, every toilet mfr would offer it, but it cannot be done. The only safe way to connect a toilet to onboard fresh water is with the use of an electric solenoid that allows the toilet to use pressurized water...which means only electric toilets can use onboard fresh water. However, most toilet mfrs do make both electric toilets and conversion kits that offer a choice of either a seawater pump or a pressurized water solenoid. They use a little more water than SeaLand CLAIMS the V/Flush needs, some actually use fewer AH (draw is higher, but running time is so much shorter)...all the advantages of a VacuFlush, plus maceration...and for a tiny fraction of the cost of a VacuFlush! Whether you want to convert a manual to electric, or replace the whole toilet, I recommend the the Raritan Sea Era...it's available either way--and you can opt for fresh water flush with either version. Check it out on the Raritan website at http://www.raritaneng.com
